Modern xerographic laser printers primarily utilize static electricity as a mechanism of operation. Toner is stored in powder form within toner cartridges for use when forming images on paper. Perhaps the most important component of a laser printer is the photoconductor. The photoconductor generates a positive electrical charge when exposed to light during a print cycle. An electrostatic image is formed on the surface of the photoconductor by negatively discharging corresponding portions of the photoconductor. A typical photoconductor comprises a multilayered aluminum tube and may be incorporated into a toner cartridge or remain an independent component. During a print cycle, positively charged toner powder is electrostatically drawn from the toner hopper and is transferred to the negatively discharged portions of the photoconductor. The toner powder clings to the photoconductor and forms the electrostatic image on the surface of the photoconductor. Conversely, the toner powder is magnetically repelled from the remaining positively charged portions of the photoconductor. A transfer roller applies a positive charge to the back of the media. The positive charge attracts the toner image from the photoconductor and transfer the image from the photoconductor to the media. The transferred toner powder on the media passes through a fuser, where heat and pressure are applied to permanently bond the toner to the media.
Following the fusing process, a primary charge roller is charged with an alternating current (AC) electrical signal, which functions to remove any residual static charge on the drum left from the previous image. Remaining toners on the photoconductor are removed by a wiper blade and deposited into the toner cartridge waste cavity. As the wiper blade is constantly in contact with the photoconductor, friction can potentially cause damage to the surface of the photoconductor, directly affecting image quality. More serious issues such as blade flipping can occur, causing the laser printer motor drive to fail or causing the wiper blade to drag toner across the surface of the photoconductor, leaving a layer of toner on the sheet of paper. In the worst case scenario, the wiper blade may crack or snap, breaking contact with the surface of the photoconductor and causing the removed toner in the cartridge waste cavity to leak. A conventional solution for reducing friction is repurposing toner as a lubricant on the photoconductor although this directly affects the image quality of a laser printer. An alternate solution involves the application of a solution such as zinc stearate to the photoconductor prior to assembly of the toner cartridge. However, the solution is applied manually and can be rather tedious and unrepeatable. The present invention seeks to address the previously discussed issues and provide a practical, convenient, and repeatable solution.
The present invention is a lubricant that is applied to the wiper blade of a photoconductor in order to reduce friction between the wiper blade and the photoconductor surface. The present invention seeks to reduce the friction between the wiper blade and the photoconductor surface while maintaining contact between the two components. This prevents wear and damage to the wiper blade and the photoconductor. The present invention accomplishes this without compromising print quality. The lubricant is applied to the wiper blade prior to installation by any liquid coating application technique including, but not limited to, dipping, spraying, flow coating, and applicator brushing. Following application, the blade and coating are heated in an air circulation oven for a specified period of time.